Option population analyses

When activating this option you first have to specify whether the population analysis (PA) should be performed in the CAO (default) or AO basis. Afterwards define will ask you whether you want to perform a Mulliken population analysis. In this case, the following submenu will be displayed:

add or delete one or more special options for a
mulliken population analysis
 option | status | description
 -------|--------|---------------------------------------
 spdf   |    F   | compute MO contributions to atomic
        |        | brutto populations
 molap  |    F   | compute MO contributions to atomic
        |        | overlap populations
 netto  |    F   | compute atomic netto populations
 irpspd |    F   | compute IRREP contributions to atomic
        |        | brutto populations
 irpmol |    F   | compute IRREP contributions to atomic
        |        | overlap populations
 mommul |    F   | print electrostatic moments resulting
        |        | from atomic charges
 -------|--------|---------------------------------------
 -<option>   : switch off <option>
 * or q(uit) : leave this menu

Here you can activate several optional quantities to be computed along with the Mulliken PA. To switch on one or more of these options you must enter the corresponding option keywords, e.g. spdf netto for computation of atomic neto populations and MO contributions to atomic brutto populations. The status flags for these tasks will then change from F (false) to T (true). To switch off any option you simply have to enter the corresponding keyword preceded by a `-', e.g. -netto for disabling calculation of atomic netto populations.

After having left the Mulliken PA section you will be asked whether a population analysis based on occupation numbers (a modified Roby-Davidson PA) should be performed by moloch. When typing y you will see the following submenu, where you can switch on several special options for the PA in the same manner as described above.

add or delete one or more special options for a
population analysis based on occupation numbers
 option  | status | description
 --------|--------|----------------------------------------
 momao   |    F   | compute MO contributions to modified
         |        | atomic orbital (MAO) occupation numbers
 maodump |    F   | dump all MAOs onto standard output
 maofile |    F   | write MAOs onto a separate file
 select  |    F   | write only those MAOs which have been
         |        | employed in the population analysis
 all     |    F   | write all MAOs
 --------|--------|----------------------------------------
 note that the options select and all are complementary
 -<option>   : switch off <option>
 * or q(uit) : leave this menu

Afterwards you have the possibility to change the criterion to be applied for the selection of modified atomic orbitals (MAOs) within the following little submenu:

global criterion for selection of Modified Atomic Orbitals (MAOs) :
-------------------------------------------------------------------
 MAOs are employed if 'atomic' density eigenvalues
 exceed a threshold of  .1000
-------------------------------------------------------------------
 specify the appropriate option if you want to use another
 global criterion for selecting MAOs
 option  | status | description
 --------|--------|---------------------------------------
 eig <r> |    T   | select by eigenvalues of the
         |        | 'atomic' density matrices
 occ <r> |    F   | select by occupation numbers
 --------|--------|---------------------------------------
 <r> is the selection threshold (DEFAULT= .1000    )
 * or q(uit) : leave this menu

The criterion applied by default is the so-called atomic density eigenvalue with a threshold of 0.1. You can switch the criterion to occupation numbers by entering occ. If you also want to change the threshold, you just have to append its new value to the selection keyword, e.g. occ .2. Finally you can select or disable various options in connection with the computation of shared electron numbers (SEN) within the following menu:

actual settings for data group $shared electron numbers
 2-center shared electron numbers will be computed;
 values are printed if absolute value exceeds    .0100
 3-center shared electron numbers will be computed;
 values are printed if absolute value exceeds    .0100
 4-center shared electron numbers will be computed;
 values are printed if absolute value exceeds    .0100
add or delete one or more options for the
computation of Shared Electron Numbers (SEN)
 option  | status | description
 --------|--------|----------------------------------------
 2c <r>  |    T   | compute 2-center SEN and print if
         |        | |SEN| > <r> (DEFAULT =  .1000E-01)
 3c <r>  |    T   | compute 3-center SEN and print if
         |        | |SEN| > <r> (DEFAULT =  .1000E-01)
 4c <r>  |    T   | compute 4-center SEN and print if
         |        | |SEN| > <r> (DEFAULT =  .1000E-01)
 --------|--------|----------------------------------------
 nosym   |    F   | switch off use of symmetry
 orbs    |    F   | compute orbital contributions to SEN
 irreps  |    F   | compute irrep contributions to SEN
 --------|--------|----------------------------------------
 -<option>   : switch off <option>
 * or q(uit) : leave this menu

The procedure for changing the options is the same as described above. By default calculation of 2-, 3- and 4-center SENs will be enabled with thresholds of 0.01 each.